How can I have my TSS from strength workouts calculated by (TSS = RPE x duration). I know I can manually adjust my TSS for the session and adjust how much it contributs to my fitness and fatigue, but is there a way to have it automatically calculate the TSS for me based on my RPE?
There is already the built-in S-RPE value, if you enter RPE it calculates automatically duration x RPE
Thank you for your quick response!
To clarify my question, it’s regarding having TSS calculated from strength workouts not s-RPE.
Note: If you are thinking of Dr. Carl Foster’s specific Session RPE (sRPE) method, that calculation does not output TSS directly; instead, it multiplies total session duration in minutes by the RPE (1–10) score to yield arbitrary training load units (e.g., 60 minutes × RPE 5 = 300 sRPE units). These numbers are usually significantly high (6-10X) compared to typical TSS scores from power, pace or hr based calculation. [1]
To predict Training Stress Score (TSS) using Session RPE (sRPE) when power or precise heart rate data is unavailable, you can use either the Joe Friel RPE-to-TSS/Hour Lookup Method or the Formulaic Intensity Factor (IF) Approximation Method. Both approaches rely on a standard 1–10 RPE scale to estimate the physiological workload based on your subjective effort and duration. [1, 2, 3]
Method 1: Joe Friel’s RPE-to-TSS/Hour Lookup Table
| Overall Session RPE (1–10) | Descriptor | Estimated TSS per Hour |
|---|---|---|
| 1 | Very, Very Easy | 20 |
| 2 | Easy | 30 |
| 3 | Moderate | 40 |
| 4 | Somewhat Hard | 50 |
| 5 | Hard | 60 |
| 6 | Harder | 70 |
| 7 | Very Hard | 80 |
| 8 | Threshold Effort | 100 |
| 9 | Near Maximal | 120 |
| 10 | Maximal | 140 |
Method 2: The Intensity Factor (IF) Approximation Formula
I currently have to do this manually for each of my RPE based sessions but was wondering if there’s currently a feature to have this done automatically?
I then toggle how I believe each type of session affects my fitness and fatigue:
Do you sync RPE automatically to intervals?
If so, you can create a custom activity field which calculates RPE * duration in hours or whatever formula you want to use, and override the load value. If you enter RPE inside intervals, you have to reanalyse the activity to run this script to override the load value.
I do sync RPE automatically, how do I create a custom activity field for the different activites?
Thank you again!
Here an example
there was another big thread with an example, though I would add the acitivity type (if statement) to override the value only for certain activity types:
so it will be something like:
{
let ans;
if(activity.type == 'WeightTraining')
{
ans = activity.icu_rpe * activity.elapsed_time / 3600;
}
else if(activity.type == 'Badminton')
{
// some other formula
}
// if you want to override, add the next line:
activity.icu_training_load = ans || activity.icu_training_load;
ans;
}
I created a Javascript to quantify TSS from weightlifting RPE. I thought I would share it here and I made it publicly visible to share with the rest of the community under Weight Training TSS:
{
if (activity.type === “WeightTraining”) {
// Get duration in hours from elapsed time
let durationHours = activity.elapsed_time ? activity.elapsed_time / 3600 : 0;
// Retrieve perceived exertion (1-10)
let rpe = activity.icu_rpe;
if (rpe && durationHours > 0) {
let tss = durationHours \* Math.pow(rpe / 10, 2) \* 100;
// Update native fitness load in Intervals.icu
activity.icu_training_load = Math.round(tss);
}
}
}
Is there a way to retroactively add RPE in bulk?